When drugs targeting the gut have effects in the brain, serotonin receptors are usually involved and it's 5-HT4 this time. Taking carbidopa (or benserazide, another peripheral decarboxylase inhibitor) along with prucalopride can potentially enhance the memory effects by preventing gut metabolism.

Blocking 5-HT6 also improves memory (in mice) but it seems to come with circadian disruption.